_qt5_ rebased to version 5.9.2
The _qt5_ packages have been upgraded to upstream version 5.9.2, which provides a number of bug fixes and enhancements over the previous version. Notably, _qt5_ now contains:
* improved performance and stability
* long term support
* improved C++11 support - note that Qt 5.9 now requires C++11 compliant compiler
* Qt Quick Controls 2 - a new module with support for embedded devices